Strength and bond characteristic of UHPC pastes with quaternary binders

In the present research, UHPC pastes are designed with quaternary binders, namely Portland cement, slag cement with 50% of ground granulated blast slag, limestone powder and micro/nano silica, at a relatively low water-to-powder ratio of 0.2. The compressive strengths
of UHPC pastes are measured and analysed after the curing age of 28 days and 56 days, respectively. The fibre-to-matrix bonding properties of UHPC pastes are characterized after 56 days. The results show that it is possible to use those quaternary binders system to design UHPC
matrix with compressive strength ranging between about 140 MPa and 180 MPa at a relatively low water content. Slag and limestone powder can greatly improve the sustainability without sacrificing too much strength and fibre-to-matrix bonding force of UHPC pastes. 5% micro silica contributes to higher compressive strength of UHPC pastes containing Portland cement, while 3% nano silica has higher efficiency than 5% micro silica for mixtures with slag cement.